Hybrid polymer composite materials. Part 2. Preparation technology

2020 ◽  
pp. 8-13
Keyword(s):  
Composite Materials ◽  
Impact Toughness ◽  
Polymer Composites ◽  
The Other ◽  
Polymer Materials ◽  
Hybrid Polymer ◽  
Preparation Technology ◽  
Advantages And Disadvantages ◽  
Hybrid Polymer Composite ◽  
The One

The main methods (pressing and winding) of the processing of hybrid polymer composites to obtain items were examined. Advantages and disadvantages of the methods were noted. Good combinations of different-module fibers (carbon, glass, boron, organic) in hybrid polymer materials are described, which allow one to prepare materials with high compression strength on the one hand, and to increase fracture energy of samples and impact toughness on the other hand.

Fiber-based hybrid polymer composites for aviation: A review

2020 ◽  
pp. 126-138
Author(s):  
E. D. Kolpachkov ◽  
A. O. Kurnosov ◽  
A. P. Petrova ◽  
A. E. Raskutin
Keyword(s):  
Composite Materials ◽  
Polymer Composites ◽  
Polymer Composite ◽  
Classification Criteria ◽  
Polymer Composite Materials ◽  
Hybrid Polymer ◽  
Distinctive Features ◽  
The Creation ◽  
Hybrid Polymer Composite

This article discusses the main classification criteria for fiber-based hybrid polymer composite materials. Their distinctive features are analyzed; examples of hybrid PCMs are given. The experience of FSUE VIAM in the creation of hybrid PCMs is considered.

Cycles in symbol production? A new model to explain concentration, diversity and innovation in the music industry

Popular Music ◽  
1995 ◽  
Vol 14 (1) ◽  
pp. 55-93 ◽  
Author(s):  
Michael Christianen
Keyword(s):  
Negative Correlation ◽  
Music Industry ◽  
The Other ◽  
Recording Industry ◽  
Cultural Goods ◽  
New Model ◽  
Advantages And Disadvantages ◽  
Factors Influencing ◽  
Using Data ◽  
The One

With the publication of the article ‘Cycles in symbol production’ (Peterson and Berger 1975) a discussion started concerning the advantages and disadvantages of the production of cultural goods under market conditions. The analysis by Peterson and Berger showed a negative correlation between concentration in the recording industry, on the one hand, and the diversity and innovativeness of the music, on the other. Repetition of the analysis using data from the 1980s (Burnett 1990; Lopes 1992) has shown that for this period Peterson and Berger's hypotheses should be rejected. Is there a connection between concentration and diversity and innovation? Are there cycles in symbol production? There seems to be no conclusive answer. In this article, I will attempt to clear up this matter. First, I will repeat the analysis of the relation between concentration and diversity/innovation, using the same model as Peterson and Berger, but with different definitions for the variables concentration, diversity and innovation. Then I will suggest a new model, which can be helpful in uncovering other factors influencing diversity and innovation in the music industry. I will come to that later. Let me first give the reader a brief overview of previous research.

scholarly journals DEVELOPMENT OF THE MODEL OF STUDENTS’ INDEPENDENT WORK UNDER CONDITIONS OF DISTANCE LEARNING

2021 ◽  
pp. 273-289
Author(s):  
Olena Osadcha
Keyword(s):  
Distance Learning ◽  
Information Technologies ◽  
The Other ◽  
Advantages And Disadvantages ◽  
Other Hand ◽  
The One ◽  
Independent Work ◽  
Further Development

The article deals with the development of the model of students’ independent work under conditions of distance learning. The importance of the research into this problem is determined, on the one hand, by the growing possibilities of using various information technologies and, on the other hand by the necessity to adapt to the conditions of today’s world where independent work of students is becoming increasingly important. The advantages and disadvantages of distance learning have been explored. The author studied the role of independent work in the formation of the professional competences of students. The issue of modeling in the area of education has been tackled. The approaches to the development of the model of independent work have been identified and analyzed. The components of the model, such as the goal, the tasks, the content, the methods, the means and evaluation of results have been determined and characterized. The prospects of further development of this research are related to the exploration of models of independent work of students majoring in different areas.

Post-Fatigue Creep and Stress Relaxation Response of a Hybrid Polymer Composite

2017 ◽  
Author(s):  
Raghu V. Prakash ◽  
Monalisha Maharana
Keyword(s):  
Stress Relaxation ◽  
Polymer Composites ◽  
Polymer Composite ◽  
Fatigue Loading ◽  
Synthetic Fiber ◽  
Relaxation Response ◽  
Hybrid Polymer ◽  
Fatigue Cycling ◽  
Creep And Stress Relaxation ◽  
Hybrid Polymer Composite

Polymer composites have a characteristic, composition specific visco-elastic property which influences the damage progression during fatigue cycling. While some researchers have studied the time dependent constitutive response of polymer composites during the first cycle of fatigue loading, very few have experimentally investigated the dependence of visco-elastic response of built-up polymer composite materials at various stages of fatigue cycling [1]. Our earlier studies on fatigue response of polymer composites focused primarily on the stiffness degradation as a function of applied cycles of loading, which represents the gross response of the material [2]. While doing such an experiment, complimentary experimental techniques to measure the temperature evolution was attempted through the use of infrared thermal imaging technique, which gave some insight into the change in temperature response as a function of fatigue cycling. However, there was no systematic measurement of creep and stress relaxation response of the composite material as a function of induced fatigue damage. The present paper describes the results of creep and stress-relaxation obtained during uni-axial fatigue loading of a hybrid polymer composite material. For this purpose, a woven carbon fiber mat was chosen as the synthetic fiber and Flax fiber in the unidirectional form was chosen as the natural fiber that is laid between the two layers of woven carbon fiber mat. Epoxy LY 556 and hardener Araldite® was used for building up of composite laminate by hand-lay-up technique. Dog-bone shaped tensile specimens with a gage width of 13 mm and gage length of 57 mm were extracted from the 250 × 250 mm sq. plate laminate of 2.1 mm thickness using a numerical controlled milling machine. The specimens were tested at 35% of their median tensile strengths under fatigue at a positive stress ratio (Pmin/Pmax) of 0.1 in tension-tension loading. Prior to start of fatigue loading, the specimens were held in load control and the strain in the gage length was measured for understanding the creep response over 2500 seconds. For stress-relaxation characterization, the specimens were held in extensometer control over a period of 2500 sec. The creep and stress relaxation tests were carried out after periodic intervals of fatigue cycling. It was observed that in the case of un-impacted specimens, the creep rate is consistent with the stiffness variation, which in turn, is dependent on the number of fatigue cycles - till it showed signs of de-lamination. Thereafter it was governed by the woven synthetic fiber response. Similarly, the stress relaxation response was found to decrease with increasing fatigue cycles. In case of impacted specimens, the local deformation had a prominent role in terms of creep and stress relaxation response.

scholarly journals Systematization and analysis of approaches to assessing the competitiveness of business entities

2018 ◽  
Vol 193 ◽  
pp. 05077
Author(s):  
Vadim Krivorotov ◽  
Aleksandr Tarasenko ◽  
Evgeniy Tikhanov ◽  
Petr Chepur ◽  
Alesya Gruchenkova
Keyword(s):  
The Other ◽  
Multivariate Models ◽  
Management Decisions ◽  
Competitive Position ◽  
Advantages And Disadvantages ◽  
Other Hand ◽  
Business Entities ◽  
The One

Assessment of competitiveness is an objective need of every business entity seeking to maintain or improve their own competitive position and make informed management decisions. The authors propose to classify the diversity of methods of assessment of the competitiveness of the enterprise through three main approaches: graphic, factor and value. In order to identify the advantages and disadvantages of each of the approaches described by the authors, the content of the main methods used in the study was analyzed. It is concluded that there is no universal tool for assessing the competitiveness of the enterprise, which is due to, on the one hand, the limited reliability and low estimates obtained by using matrix and product methods, and on the other hand, the complexity and cost of the estimates using existing multivariate models.

scholarly journals Progress of Bio-Calcium Carbonate Waste Eggshell and Seashell Fillers in Polymer Composites: A Review

2020 ◽  
Vol 4 (2) ◽  
pp. 70 ◽  
Author(s):  
Stephen Owuamanam ◽  
Duncan Cree
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Environmental Impact ◽  
Impact Toughness ◽  
Flexural Strength ◽  
Polymer Composites ◽  
Polymer Materials ◽  
Future Research ◽  
Carbonate Mineral ◽  
Thermoset Polymer

Disposal of massive amounts of eggshells and seashells from processing industries is a challenge. In recent years, there has been a focus to reuse these waste resources in the production of new thermoplastic and thermoset polymer materials. This paper reviews eggshell and seashell production by country and provides a perspective on the quantity of bio-calcium carbonate that could be produced annually from these wastes. The achievements obtained from the addition of recycled bio-calcium carbonate fillers (uncoated/unmodified) in polymer composites with a focus on tensile strength, flexural strength and impact toughness are discussed. To improve compatibility between calcium carbonate (mineral and bio-based) fillers and polymers, studies on surface modifiers are reviewed. Knowledge gaps and future research and development thoughts are outlined. Developing novel and innovative composites for this waste material could bring additional revenue to egg and seafood processors and at the same time reduce any environmental impact.

Evaluation of the Resource Efficiency of Foundry Technologies: Methodological Aspect

2014 ◽  
Vol 1040 ◽  
pp. 912-916 ◽  
Author(s):  
Igor B. Ardashkin ◽  
Alexey N. Yakovlev ◽  
Nikita Martyushev
Keyword(s):  
Resource Efficiency ◽  
The Other ◽  
Methodological Aspect ◽  
Efficiency Evaluation ◽  
Expert Evaluation ◽  
Economic Aspects ◽  
Advantages And Disadvantages ◽  
Assessment Techniques ◽  
Methodological Assessment ◽  
The One

A brief analysis of the approaches to the evaluation of foundry technologies’ resource efficiency is presented. It is revealed that when evaluating resource efficiency researchers apply different criteria which do not allow them, on the one hand, to more objectively estimate the parameters and, on the other hand, to relate and compare the advantages and disadvantages of each of the assessment techniques. Representatives of one of the approaches to resource efficiency evaluation focus on determining the technological side, while representatives of the other approach emphasize the priority of the technological and economic aspects. Taking the example of analysing the problems of the technology of casting by gasified models, it has been demonstrated that the evaluation of resource efficiency cannot be unambiguous. Constant monitoring of the process is required. The authors come to conclusion that it is the method of expert evaluation that allows being more flexible in the evaluation of the resource efficiency of foundry technologies. The result of the conducted methodological assessment is the developed formula for estimating the resource efficiency of foundry technologies.

Adhesive Wear of Polymers

1977 ◽  
Vol 99 (4) ◽  
pp. 396-400 ◽  
Author(s):  
V. A. Belyi ◽  
A. I. Sviridyonok ◽  
V. A. Smurugov ◽  
V. V. Nevzorov
Keyword(s):  
Adhesive Wear ◽  
Contact Region ◽  
The Other ◽  
Polymer Materials ◽  
Cohesive Failure ◽  
Adhesive Interaction ◽  
Antifrictional Materials ◽  
Friction Polymers ◽  
Wear Products ◽  
The One

Adhesive wear is a characteristic but inadequately studied type of wear of polymer materials. In local regions of real contact an intensive molecular (adhesive) interaction is observed under rubbing conditions, which is stronger than the bonds between individual elements in the supermolecular formations or in polymer molecules, leading to cohesive failure of the material. Wear products can escape from the contact region as gases or as solid substances, or they can form a “third body”, i.e., a transferred layer of one material is deposited on the surface of the other. The direction, mechanism, and character of the occurring processes are determined, first of all, by the structures of the interacting materials. To know the mechanism of adhesive wear enables one to predict dangerous failures of the surfaces under rubbing due to seizure, on the one hand, and to find ways of governing the frictional interaction and create efficient self-lubricated polymer-based materials on the other hand. One of the efficient ways of providing minimum wear in metal-polymer friction pairs is to govern the process of developing “friction polymers” and to use mixtures of polymers having different thermophysical properties as antifrictional materials.

scholarly journals Experimental Research on Roselle / Glass Fibre Hybrid Polymer Composites

2019 ◽  
Vol 9 (1) ◽  
pp. 4665-4669
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Polymer Composites ◽  
Experimental Research ◽  
Glass Fibre ◽  
Hybrid Polymer ◽  
Lower Volume ◽  
Polyester Composites ◽  
The Impact

Varieties in tractable and sway properties of Roselle fiber strengthened polyester composites brought about by the expansion of glass fiber have been investigated. Roselle fiber in mix with glass is magnificent for making economically savvy composite materials. The impact of the plan of glass and Roselle fiber in the readiness of composites have likewise been examined. Direct increment in rigidity is noted because of the expansion of glass. Be that as it may, when lower volume portion of glass is utilized, a cozy blend of Roselle fiber and glass demonstrates the most elevated rigidity. The effect quality demonstrates the most noteworthy worth when a glass volume part of 0.12 is utilized

scholarly journals “THE LAWYER MONOPOLY” SHOULD IT BE MOVED?

2020 ◽  
Keyword(s):  
Transition Period ◽  
Point Of View ◽  
The Other ◽  
Gradual Transition ◽  
Court Cases ◽  
Advantages And Disadvantages ◽  
The Law ◽  
The One ◽  
Representation Of Interests ◽  
Autonomous Republic

The article deals with the debate on the so-called “lawyer monopoly” on representation of interests in court. The Law of Ukraine "On Amendments to the Constitution of Ukraine (on Justice)" adopted on June 2016, dated June 2, 2016, No. 1401-VIII literally divided the legal community into two camps: "for" and "against" the so-called "monopoly of the Bar". It should not be denied that both supporters of this reform and its opponents have strong arguments in favor of their beliefs. In the last four years, both camps have made new arguments in support of their point of view. But every year, since the passage of the aforementioned law, calls for change have become louder. This is due to the fact that, on the one hand, the aforementioned law introduced a gradual transition to representation in all judicial instances only by a lawyer and a prosecutor, and on the other, by the fact that the proposal to exclude the rule of “lawyer monopoly” from the Constitution of Ukraine was one of the first bills of President Vladimir Zelensky. Several steps have now been taken to abolish this "monopoly" but the whole path has not yet been completed. Thus, from January 1, 2020 the Law of Ukraine 390-IX “On Amendments to Certain Legislative Acts of Ukraine on Expanding the Possibilities of Self-Representation in the Court of State Authorities, Bodies of the Autonomous Republic of Crimea, Local Self-Government Bodies and Other Legal Entities, Whatever Their Order, came into force creation ”, but the bill announced by the President No. 1013 of 29.08.2019 still remains within the walls of the Verkhovna Rada of Ukraine. This leads to some contradictions and inconsistencies in court cases regarding who can participate in litigation. In the article the author highlights the advantages and disadvantages of "lawyer's monopoly", as well as the problematic issues of the so-called transition period.

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